الفهرس 
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Abstract
This study was carried out through two trials at the Animal
Experimental Farm. Faculty of Agriculture at Moshtohor. Zagazig
University. Banha Branch. In the first trial. 30 ewes from
Ossimi. Rahmani and Ossimi-Rahmani crosses were used in this
study to investigate the effects of breed group and parity on
body weight. body measurements and wool characteristics of ewes.
Studies on growth efficiency and wool traits were performed
on male and female lambs of three breed groups from birth to
yearling to investigate the effect of breed group and sex factors
on growth performance and wool traits. In the second trial. a
fattening experiment was carried out using castrated and uncastrated
Ossimi and Ossimi-Rahmani crossbred lambs to study
carcass traits and constructing predition equations of carcass
traits from body weight and measurements of male lambs at different
ages. The most important result~ obtained could be summarized
as follows:
5.1 Growth TrAits (body weight, daily gain and body measurements:
1. The differences among means of body weight of Ossimi.
Rahmani and Ossimi-Rahmani crossbred lambs at birth. 2. 4
and 6 months of age were statistically non-significant.
However. at 8. 10 and 12 months of age. Ossimi lambs were
significantly heavier than Rahmani and crossbred lambs.
The differences in body weight due to breed-group effect
were non-significant at birth, 2. 4 and 6 months of age
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and significant at 8. 10 and 12 months of age.
The coefficients of variation of lamb’s body weight
slightly differed.
Ossimi ewes were significantly heavier than Rahmani and
the crossbred ones were inbetween them. Differences in
body weight of ewes due to breed group and parity were
non-significant. Males were heavier than females at
birth. 2. 4. 6. 8. 10 and 12 months of age and the differences
were highly significant (P< 0.0001).
2. The averages of daily gain decreased gradually from birth
to yearling in the three breed groups. During the periods
from 2-4. 4-6. 6-8 and 8-10 months of age. Ossimi lambs
grew better than the other two breed groups. Differences
due to breed-group effects. with respect to daily gain for
the intervals 0-2. 2-4. 4-6. 6-8. 8-10 and 10-12 months of
age proved to be non-significant except the interval 4-6
months of age which proved to be significant (P< 0.05).
The coefficients of variation of lamb’s daily gain tor the
three breed groups at each of age were nearly the same.
Male lambs gained more than females during the pre-weaning
and post-weaning stage. the differences were highly significant
(P< 0.01 and P< 0.0001).
3.d. Differences in body length due to breed-group effect were
non-significant at 2. 4. 6. 8. 10 and 12 months of age.
while sex effect was highly significant at all these ages
and males exceeded females in this character.
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b. Differences in height at weithers due to breed-group
effect were non-significant at all ages. except at 2 and
12 months of age. Sex effect was highly significant at all
ages and males exceeded females in height at withers.
c. Differences in each of heart girth. chest width and chest
depth due to breed group effect were highly significant
(P< 0.01 and P< 0.001) at all ages. excep~ at 2 months of
age. The Ossimi lambs had relatively higher heart girth.
chest wigth and chest depth than other two breed groups at
all ages. except at 2 months of age. Sex effect was significant
(P< 0.05 & P< 0.0001) at all ages. while the
interactions between breed group and sex were almost nonsignificant.
d. Differences in thigh circumference due to breed-group
effect were highly significant (P< 0.01 and P< 0.001) at
4. 6 and 8 months of age only. Ossimi lambs had higher
thigh circumference than Rahmani and cross lambs. Sex
effect was hihgly significant at all ages except at 2
months of age as males exceeded females in this character.
The interactions between breed groups and sex were highly
significant (P< 0.01) only at 8 and 10 months of age.
e. Differences in cannon circumference due to breed-group
effects were highly significant (P< 0.01) only at 8 months
of age. Ossimi lambs had higher cannon circumference than
the other two breed groups. Sex effect was almost highly
significant at all ages as males exceeded females in this
character.
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f. Differences in heart girth and chest width of the sdult
ewes due to breed-group effect were significant and Ossimi
ewes exceeded the other two breed groups in these two
dimensions. while Rahmani and crossbred ewes were nearly
the same.
4. At all ages. from 2 UP to 12 months. live body weight was
highly significantly corr~lated with daily gain and seven
body measurements. The coefficients of correlation between
daily again and each of body measurements at 2 months of
age were mostly high while at and after weaning. the coefficients
were generally moderate and high. Body length was
possitively highly correlated with each of heart girth and
height at withers at all ages. and was highly correlated
with chest at pre-weaning. At 2 months of age. high possitive
coefficients of correlation were obtained between
(HW) and each of HG and CWo while the coefficients of correlation
between HW and each of CD. TC and CC were moderate.
At 2 months of age. positive coefficient of correlation
was obtained between HG and CWo At 4 months of age
high coefficients were obtained between HG and each of CD
and Te. while at 6. 8. 10 and 12 months of age. all the
coefficients between HG and each of CWo CD..TC and CC were
high. At all ages except at 4 months of age. the coefficients
of correlation were almost high and possitive
between CW and each of CD. TC and ee. At all ages the
coefficients of correlation were almost high and possitive
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between CD and each of TC. CC. The coefficients of correlation
between TC and CC at post-weaning till yearling
were high and possitive.
5.2. Wool Traits:
1. Differences in the first grease fleece weight due to
breed-group effects were highly significant. The average
grease fleece weight at yearling of each of Rahmani and
the Ossimi-Rahmani crossbred lambs was significantly more
than that of Ossimi lambs and the differences in fleece
weight between Rahmani and the crossbred were nonsignificant.
The average of grease fleece weight of adult
Rahmani ewes was significantly more than each of the other
two breed groups (Ossimi and crossbreds) and the differences
due to breed-group effect on fleece weight were
highly significant. The fleece weight of the three breed
groups showed that the yearling lambs produced heavier
greasy fleece weight than the adult ewes.
Male lambs recorded heavier weight for the first greasey
fleece than females and the differences between male and
females were highly significant.
The regression of greasey fleece weight on age of ewe was
13 gm/mth. which indicate significant effect of age on
greasey fleece weight.
,2. Rahmani lambs and ewes exceeded significantly in clean
wool % both the other two breed groups.
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Sex of lambs was found to have highly significant effect
on clean wool percentage at all ages and males recorded
higher percentage than females.
3- Fleece of Ossimi lambs contained more innercoat fibers
than the other two breed groups and that of Rahmani and
the crossbred lambs had higher percentages of outerCQat
and kemp fibers. Differences among breed groups due to (
innercoat. outercoat and kemp fiber percentage were highly
significant.
Comparisons among fiber type ratios of the breed
groups of the adult ewes showed that Ossimi and crossbred
fleeces had nearly similar innercoat and outercoat percentages.
which were significantly higher than the percentages
of Rahmani ewes. Rahmani ewes had markedly
higher kemp percentage than the other two breed groups.
Differences due to breed groups among innercoat and kemp
percentages were highly significant while those among outercoat
percentages were non-significant.
Sex effect from 2 to 12 months of age of lambs had
no significant contribution to variation of wool component
ratios. The effect of interaction between breed-group and
sex proved to be significant in case of outercoat and kemp
percentages. The highest proportion of the innercoat fibers
for the three breed-groups was attained at pre-weaning
age and percentages of the three breed groups were found
to decrease as age advanced. while percentages of outercoat
and kemp were found to increase.
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4. The averages of fiber diameter at 2. 4. 6. 8 and 10 months
of age. for Ossimi males and females. were less than the
averages of fiber diameter of Rahmani males and females
and the averages of fiber diameter of crossbred did not
show a particular trend. The differences in averages of
fiber daimeter between males and females showed a slight
effect of sex on fiber diameter. The average of fiber
diameter increased with advancement of age.
The averages of fiber diameter medullated of Ossimi
lambs at 2 months of age. were less than the averages of
Rahmani lambs. while at 4 and 6 months of age the averages
were nearly the same but at 8 . 10 and 12 months of age.
Ossimi exceeded Rahmani.
The averages of medulla diameter and medulla percentages
in male Ossimi fibers at all ages were less than medulla
and percentages of Rahmani males. The opposite trend
was observed in female lambs with respect of medulla
diameter.
The crossbred male and female lambs did not show a definite
tendency in medulla diameter and medull percentage.
The Rahmani ewes had the highest average fiber diameter
(Total. non-medullated and medullated compared with
Ossimi and crossbred ewes. while the crossbred ewes were
intermediate between the other two breed groups.
5. The averages of staple length of Rahmani and cross lambs
were almost similar and exceeded the average staple length
of Ossimi lambs. Male lambs proved to have longer staple
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b. Body length may be used with high accuracy at 8 and 10
months of age for predicting carcass length and with adequate
accuracy for predicting lean % of L.D.
c. Heart girth of lambs at 6 and 10 months of age and chest
depth at 8 months of age may be used for predicting fat %
of L;D. with satisfactory accuracy .